Express checkout is rarely faster. Each customer takes about 2 minutes to pay no matter how many items they buy. Each item only takes 3-5 seconds to scan. So each person at express lane is going to take about 3 minutes. While a customer with 60 items at the regular lane takes about 7.
i.e. If there are 2 customers with full cart at regular lane, but 6 at express lane. You are probably still better off at regular lane.

Of course, middle-aged women are more likely to use coupons which takes more time. I also look for impatient looking people, they are likely to move fast as well. It is the perceived value of time that you are looking for.

For cashiers, look for one in the manager’s vest at peak time. Stay away from young men and women, they are likely to be new or part-time and don’t care to improve because it is temporary gag for them. Look for someone with an older looking uniform. I also try to memorize the cashiers who are fast.

With this tactic, I rarely spend more than an hour for my weekly shopping.

I always seem to pick the slow line, with people counting coins, or just giving the whole bunch to the cashier to count, no price tag or bar code not in the system. Either it’s worst when I’m in a hurry or I’m just getting more impatient with the extra tills not being used. Why pay to install them when you can’t staff them on a Saturday peak hour??

I agree with adorita, the trick is to profile the cashiers and customers. I look for mood more than appearance (for example, anyone who looks befuddled or distracted will move slow.This observation will apply across all people no matter what their age or appearance.)
Of course, you can do this in reverse. If I’m not in a hurry, I’ll pick the slowest line so I can read the magazines! At $5.95 a pop, the National Enquirer can be read cover to cover in 5 to 10 minutes. Ka-ching!

I feel like I’m often the customer causing the hold up, ‘cuz I regularly buy items that are reduced or have a wonky price. The cashier often rings it in incorrectly, then has trouble voiding it. Wait wait wait for a clerk to verify the price, wait wait wait for the manager to authorize it. All the while I’m apologizing to the customers behind me and asking the cashier to suspend my transaction and ring others through while we wait wait wait! To anyone who has ever been behind me in line when this happens, I’m so sorry! (btw this never happens in the express lane)

I always do “profiling” at Costco and will sometimes pick a longer line because I have assessed that those ahead of me have “their act together” and are not “befuddled” (I will use that word in the coming weeks!).

At Costco: I even get behind families, because they need to leave fast.

My husband does “profiling” at the airport to get through security faster.